anderson r



ATTORNEY 3' Sheets-Sheet L \N N. NW N ER c. o. ANDERSON AUTOMATIC BRAKEADJUSTING MECHANISM Original Filed March 26, 1927 July '2, 1929.

July 2, 1929. c. o. ANDERSON R 7.3

AUTOMATIC BRAKE ADJUSTING NECHANISI Original Filed March 26, 192'? 3Sheets-Sheet 2 2, 1929- c. o. ANDERSON AUTOMATIC BRAKE ADJUSTINGMECHANISM V Original Filed March 26, 1927 3 Sheets-Sheet iNVE NTORATTORNEY l. llll llll llll Reissued ay 2, 1929.

UNITED STA TES CHARLES 0.. ANDERSON,

on OMAHA, NEBRASKA.

PAT

An'roMA'rro BRAKE-ADJUSTING MECHANISM.

Original lilo. 1,691,325, dated November 13, 1928, Seri aI No. 178,669,filed March 26, 1927. Application for reissue filed April 10, 1929.

slack or clearance between the brake-shoes and wheels when the brakesare in release a position. It is the object of my present invention toprovide, 111 brake-ad usting mechanism of the above character, certainrefinements of structure whereby toreduce to a' minimum the wear ofthenicchanism due to vibration, lack of lubrication, and theintroduction of abrasive materials into the working parts. A furtherobject of my invention is to provide means for preventing excessiveaction of the adjusting means, such as to cause separation of the adjListing-screw and the head in which said screw works. A further objectis to provide means for preventing looseness'between the workingparts orthe adjuster, whereby to enable operation thereof by the relativelysmall resisted movement of the brake-levers in so-called' bcai'nlessbrake-rigging, wherein the brake-shoes are closely associated with thetrnclelevers 111w stead of being carried at the ends of brake vbeams toWlllCll the truck-levers are'connected at the center. i

Further, it 1s an object to maintain adehnite normaloraverage frictionbetween the" V adjusting rod and the forked head, thereby not onlyavoiding rattling, due to looseness, but also preventing back lash. orslippage or therod whilethe clutch sleeve is beinginoved I reversely, i.e., moved for, the purpose'of tingitto a position for turning theadjnsting rod to take up slack. v

In theaccompanying drawings: I Figure 1 is a longitudinal section of atruck having applied tothe brake-levers at oneside thereof. an adjustingmechanism embodying myinvent'ion.

Figure 2 is a plan view of the same. 1 Figure 3 is a detail end view ofthe adjustin mechanism and a or ti on of the live trucklever.

Figure dis adetail transverse section on the line 4- -4; of Figures 5and 6. Figure 5 is a mechanism; p p

t Figure Gis a longitudinal section of the same. a

Figure 6 is a side view,partially in longig I tudinal section, showing amodified structure;

sideview of the adjusting Serial No. 354,117.

nal section of thesforked head showing a frictional' means whichprevents back lash and loosenessbetween the rotatable head and theforked head.

Referring to Figures 1 and-2, there are shown portions of a truck of atype which has recently come into use for electric railways, and whereinthe brake-rigging is commonly designated as beamless although in factthe brake-shoes are carried on brake beams. In trucks of this type, inorder to provide space for electric motors hung between the aXles 10 andthe cross-beams 11 of the truck-frame, the live and dead truck-levers ofthe brake-rigging are not connected with the central parts of thebrake-beams 12', and the main transverse portions of said beams arearranged substantially beneath the bolster 13. In this class ofbrake-rigging, in orderto attain proper equalization of thebraking-pressure at the brake-shoes 14, there are employed on eachtrucktwo live-levers 15 izing-lever 18 to which thebraking power is applied.The release-springs 19 are also connected with equalizing-lever 18. Theupper. end of each dead-lever is fulcrnmed on a link 20 connected withthe cross-beam 11.

i The intermediate portions of the levers 15 and 16 are connected withthe brake-beams 12 by brackets 21 which are secured to said beams closeto the ends thereof onwhich the shoes llare' attached, and, thebrake-shoes and beams are supportedby hanger-links 22 pivotallyconnected with the side-frames 23 of thetruck. "In the illustratedstructure the lower ends ofthe levers15' and 16 are operatively:connected with'each other by my improved brake-adjuster, which isautomatically extensible longitudinally to compensate for wearofthebrake-shoes. i

In the "bral re-rigging of the class above mentioned, and in othercases, such as in locoinotive truck and driver-"brakes, where the noted.

brake-levers are closely associated with the brake shoes, Without theinterposition of a considerable lengthof brake-beam, the movement ot thelevers in applying'and releasing the brakes is relatively small, becausesubstantially all movement of the levers is immediately effective uponthe brake-shoes, and alter the brake-shoes are in contact with thewheels very little excess movement of the levers is required tocompensate for springing of the brake-beams as the braking pressure isincreased. In applying, to such brakerigging, automatic slack adjustingmeans which. depends for its operation upon variations in the angularrelation of the live-lever and the connecting member between said leverand the dead-lever, the adjusting meansmust be of such constructionthat'it will operate eiiiciently and continue to so operate, without theexcess travel of the truck-levers usually caused by springing ot thebrake-beams; and it is this fact which necessitates certain of therefinements of structure of the slackadjusting mechanism, whichconstitutes the subject matter of this application. It will beunderstood, of course, that my improved adjusting mechanism isapplicable to the older types of brake-rigging, and is not limited tobrake-rigging of the special types above The adjuster mechanism is bestshown in Figures 3, 4, 5, 6 and 7, and, referring to said figures itwill be seen that at the end oining the live-lever 15 there is a forkedhead 24 which straddles the end of the live-lever and is pivotallyconnected therewith by the pin 25. The jaws of said forked head haveupwardly extended cheek-plates 26, formed integrally therewith andadaptedto closely embrace the sides of the lBVG1','LS best shown inFigure 3, for a purpose which will presently appear. A portion of thepin25 is extended laterally of the head to form a fulcrum for thebell-crank or rocker-27 which is retained thereon by a nut 28 screwedupon. the threaded end of the pin, a'coil spring 29 being disposedbetween said nut and the hub of the rocker to trictionally restrain.movements of the rocker about the pin, and to thus reduce wear andrattling of these parts. One arm of the. rocker extends approximatelyhorizontally andvterminates in a ball 30 which fits within a socketformed by a U-shaped flange 31 on the side of the clutch-sleeve Theother 211311101? the rocker extends up approximately parallel with thelever. 1.5, and has atorked upperend portion which straddles thelaterally p t-ejecting end of the fulcrum pin .83 Which connectst-lieleverwith.

the bracket 21 ofthe'brake-beam. One side of the forked end o tthe armis tormcd by a finger34 which has athreaded shank screwed through themain part, of the'arm, whereby the space between the jaws of the forkmay be adjusted, a lock-hut 35 being provided on the threaded shank forholding the same in adjusted position.

The head 24 has a tubular body-portion 36 over which the clutch-sleeve32 tits rotatably,

and through which is extended the rotatable adjusting-rod 37. Withinsaid tubular portion 36 said rod 37 has a conical shoulder or offset 38which fits within a conical seat provided within the bore of the head,said shoulder being held against said seat by the pres sure of a spring39 disposed around the re duced end-portion 37* of the rod and retained.thereon by a-nut 40 screwed upon the threaded end of said reducedportion. Upon the rod 37 adjacent to the end of the tubular body 36 isdisposed a conical clutch-collar 4-1 which is secured to the rod by atransverse pin Said collar 4-1 is inclosed by the sleeve 32 which isbored to provide a conical seat for engaging the collar, and the sleeveis pressed yieldingly longitudinally of the rod to frictionally engagesaid seat 32 with the clutch-collar, by means of a spring 43 dis posedaround the rod. at the end of the sleeve and held against the same by acollar 44 secured to the rod by a transverse pin 45, as shown in Figure6. The main portion of the rod 37, at the end opposite the clutchmechanism, is threaded and screwed into the thrcarb ed intermediateportion 46 of the tubular head 4-. One end of said head 46 is closed andhas a pair of aws 47, formed integrally therewith and adapted tostraddle the lower end of the dead-lever 16, the latter being pivotallyconnected therewith by a pin 48 passing transversely through any of aplurality of holes 49 in the aws. T he adjlisting-screw termed by thethreaded part of therod 37 is covered at all times by the chamberedendportions of the head 46, the open end of said head being extended tonormally engage the smooth or unthreaded portion of the rod, and thusforming the guide 50 for holding the head and rod in alignment additioually. to the screw-threaded engaging portions of said members. Inthe side of the head 46 adjacent to the closed end thereof. an openingis formed, which is normally closed by a screw-plug 5]. By connecting agrease-gun with said opening a suitable lubricant may be forced into andthrough the head, so as to flow toward the open end thereof, past theadjusting-screw, and thus tend to eject from the bore of the head anydirt, grit or abrasive m aterial which may have entered the same. Thechambered end-portions 0f the head form reservoirs for retaining aquantity of grease sufficient to lubricate the screw during an extendedperiod of use. At the upper side of the threaded intormediate portion ofthe head 46 atubular boss 51 is formed thereon, the outer end of theopening thereof being normally closed by a screw-plug 52. At the innerend of said opening, adjoining the screw, is disposed a ball 53 which.is pressed yieldingly against 1'" I thevscrew'by a coil spring 54disposed between I thereof, one side of said notch being radiallyundercut so that when the ball drops into the notch, as shown in Figure4, it will prevent; further rotation of the screw in the die the sprireduced toa minimun'iirection tending to withdraw the screw from thehead. The-other sideof the notch is so inclined that when the screw isturned so as to'enter the head the ball will he lifted out of the notchand the turning movement not interrupted.

"For use where the adjuster is subjected not only to lateral or Whippingstressesbut also to longitudinal shaking and vibration, it is desirableto prevent wear of the adjustingscrew and the threaded part of the head,by maintaining between the head and screw a longitudinal pressurewhichis constant in direction. This result is attained by the specialmeansillustrated in Figures'fi", ,8 and 9, wherein the guide member atthe open end of the head 46' .is formed as apackinggland screwed intothe head, the gland being recessed at its inner end to receive a packing56 which is engaged the end of a sleeve 57 fitting slidably over the rod37. At its inner end the sleeve 5? engages a spring 58 disposed aboutthe rodfand the inner end'of said spring engages a nut 59 which isscrewed onto the threaded portion of the adjusting-rod. The nut 59 iscyline drical "except for a V-shaped projection 59 at one side which isextended into a similarly formedpocket 60 at the side of the head,whereby rotation of the nut within the'hea'd is prevented, whilelongitudinal movement, is pern itted. In assembling the parts the nut 59is inserted edgewise through the open end of the head, and'turned to atransverse position after theprojection 59' is in positionto enter thepocket60. The rod then screwed through the nut, sodas to projectslightly p'astthe inner face thereof,

before starting to enter the adj acentthreade d portion of the head.When the screw 1s started in said threaded portion, the nut Wlll rmaintain its longitudinal position relative thereto, asthe rotation ofthe screw Wlll cause it to advanceequallythrough both the nut and'thehead." The assembly is completed by inserting the spring 58 and sleeve57, then screwing the glandet)" into the head, whereby 58 is compressedagainst the side which is thus caused to exert a The m of the nut,thrust upon the ad usting-screw.

, strength of the spring 58 is such that thelongitiiidinal pressurebetween the partsremains constant in direction, regardless of anyshal'iing or vibratio-nto which the same are subjectechand wear of thethreads by rattling or hammering from. such vibration is thereby Inconsidering the operation of the ad.- juster as 'awhole, it will befirstnoted that the clutcl'i-sleeve 32 is pressed against theclutch-cone 41 with a constant'and uniform pressure, proportional to thestrength of the spring 43, and any rotational movements of the sleevethus tend uniformly to be imparted; to the adjusting-screw or red 37 bythe frictional clutch connection. The conical shoulder 38 of theadjustingaod, by being pressedinto the seat therefor in the head 24:,forms a clutch-like frictional connection between said head and theadjusting rod. The spring 39 keeps the longitudinalpressure at theconical shoulder constant in direction, as the pressure of said springis greater than any tensile stresses to which the adjuster'is normallysubjected, but the total pressure stantially in proportion to thebraking" pressure exerted upon the shoes. v t

Duringa normal brake-applying movement of the live-lever, such as occurswhen the slack or clearance between thebrakeshoes and wheels is notexcessive, the change in ti'ie angular relation of the live-lever to theadjuster mechanism merely causes the fulcrum-pin 33 to movebetween theaws of the rocker 27, and causes no movement of the rocker relative ,to'the head. 24. then the slack is excessive l'iowever, the increasedn'iovement of the live-lever in applying the brakes causes the pin '33to engage thefinger .or jaw of the rocker and to move thelatter slightlyabout its: fulcrum on the pin 25; Such movement of the rocker iscommunicarted to the clutch-sleeve 32 by the ball-head 30 of the lowerrocker-arm, causing the clutch-sleeve to be rotated slightly relativelytothe headQt, and when the brakes are then releasetilthe movement isreversed and the clutch-sleeve is rotated slightly. in the oppositedirection.

These oscillating, or alternat n rections be imparted. ec 'ually to theadjusts in -rod no effective ad'ustment ofthe rod willjbe' caused, andthe length of the brakd rotative, movements {of the clutch-' slee e tendtobeimparted by said sleeve to the lever-ccnnection, formed by the heads24 and 46 and the rod 37, will be unchanged. ation of the rod 37 occurs,however, when the clutch connection between the sleeve 32 and collar llis caused to slip during the moven'ient in one direction. Theclutch-friction is so proportioned that such slipping of the clutchconnection will occur during the resisted portion oi? the brake-applyingmovei'neut, or after the brake-shoes have engaged the wheels and begunto exert some pressure thereon, whereby the longitudinal compression ofthe bralze-lever-connection causes an increase of the frictionalresistance to retation oi the screw ithin the head 46 and oi? theconical shoulder 58 within the seat therefor in the head 24. After such.slippage of the clutch has occurred during a brahe-applying movement,then at the end of the succeeding brake-releasing movement theadjusting-screw is turned slightly in the direction required to elongatethe ti'uclr-lever connection and reduce the slack. If a sufficientreduction of the slack is effected, subsequent applications of thebrakes will cause no movement of the rocker and clutch-sleeve, but theadjusting action will be continued at each application and release ofthe brakes until the excessive slack is fully compensated.

As hercinbetore noted, the portion of the brakedever movement which ise'tlective to cause actuation ot the automatic slack-adjusting means, isthe resisted motion which occurs after the brake-shoes have engaged thewheels, and subsequent to the free motion during which the brakeshoesare merely being moved toward the wheels. Obviously, in brake-rigging ofthe types first herein mentioned, or in which the brake-levers areclosely associated with the brai-;eshoes, the resisted. portion of thebrake-applying motion 071' the levers is of small extent and is merelyiat which results from the slight resilience oi? the parts intermediatethe trucklevers and brake-shoes, and the slight displacement of thewheels of the truck, allowed by looseness oi? the journal-boxes andresulting from he brake-pressure against the wheels. In order that thelimited amount of resisted motion of: the levers may be fully efl'ectivein actuating the adjuster, substantially all loosencss and lost motionbetween the parts of the adjusting mechanism must be eliminated, andwear thereof cou'ipensated so that looseness will not occur after aperiod of use; In my improved adjuster the first of the several means,employed for the foregoing purpose, consists in the provision ot' thecheek-plates 26 on the head 24. Said cheek-plates limit to a minimum anyrotational movement of the head 24 about the axis of the adjusting-rod37, which might otherwise result from looseness of the pin 25 whichconnects said head Qt with'the livelever 1f The second'means forlimiting or reducing lost motion in the adjusting de vice consists inthe extension of the rod 37 entirely through the head 24, and theprovision of the spring 39 upon the extended portionot the rod, wherebythe shoulder 38 is held firmly seated in the head, rattling and wearbetween the head and rod is minimized, and a definite normal or average.friction is assured between the head and ment thereof, assures enicientlubrication of the adjusting-screw, protects the screwthreads fromcorrosion, excludes dust and abrasive material from the screw, andprovides the supplemental guide 50 to assist in maintaining thealignment of the head and screw. The lock or latch device, formed by theball 53 and the notch 55 in the adjusting-serew, prevents the accidentalwithdrawal of the screw from the head l6 by the continued operation ofthe adjusting means, should the renewal or". worn brake-shoes beneglected or loss or breakage of parts occur, tending to cause theextension of the adjuster beyond a proper range of adjustment thereof.Finally, the provision of the nut 59 and the spring 58, in the specialconstruction shown in Figure 8, causes a longitudinal pressure, constantin direction, between the adjusting-screw and the threaded part ot thehead 46, and thus prevents longitudinal play, rattling and wear betweensaid head and the screw. i

Further, the presence of the ball 53 and spring 52 tends to preventrattling of the screw, in the threaded part of the head 46 should thesame become somewhat worn and should no device such as the parts 58 and59 (Figure 8) be used, see Figure 6.

Now, having described my invention, what I claim and desire to secure byLetters Pat cut is:

1. In an automatic slack-adjuster for brakes, a brake-lever-conuectioncon'iprising terminal heads connected with the brake-levers, and anintermediate rod connecting said heads and rotatable relatively thereto,a portion of said rod being threaded and engaging threaded portion ofone head, means for maintaining between the rod and the other head alongitudinal pressure constant in direction, a clutch-sleeve mountedrotatively upon said rod and having a constant frictional a pivotallyconnected withthe brake-levers, an

intermediate rod connecting said heads and rotatablerelatively thereto,a portion of said rod being threaded and engagng a threaded portion oftthe adjacent head, and means for maintaining betweensaid rod and each ofthe heads a longitudinal pressure which is con stant 1n d1rection.

3. In a slack-adjusterv for brakes, a brakelever-connection comprisingterminal heads and an intermediate threaded rod connecting saidheads androtatable relatively thereto tovary the length of the connection, meansfor rotating said rod, means pivotally connecting said heads w th thebrake-levers, and

b means formed integrally with one of the heads and closely embracingthe ofthe respective brake-leverat a substantial distance from thepivotal axis, whereby to prevent rotative movement of said head relativeto said lover about the rod-axis when the pivotal connection of the headand lover becomes worn and loose.

4.; In aslack-adjuster for brakes, a brake lever-connection comprisingterminal heads plvotally connected with the brake-levers,

and an intermediate rod connecting said heads, said rod having at oneend a screwthrea'ded connection with one of the heads and having at theother end a shouldered reduced portion extending through the other headand rotatable therein, the shouldered portion engaging a seat thereforinsaid head, and means pressing said shouldered portion yieldinglyagainst said seat. Q I I 5. In a brake-lever connection, a rotatable adjlisting-rod having'a threat'led end-portion, a head having at one endtherecd jaws for pivotal connection with a brake-lever and having atubular body inclosing all of the tl'lreadec l portion andpart of theunthreaded portion'oi the. adjustingrod, said tubular body havingarr-internally threaded part engaged by the threaded portion of theadjusts ing-rod, a guide carried at the end of the tubular body andfitting about the unthreaded portion of the adj usting-rod, a nutdisposed upon the threaded portion of the adjusting-1nd within thetubular body between said guide and the threaded part of the body, saidnut and the tubular body inter-engaging to prevent relative rotationthereof, and a spring disposed about the rod between the guide and saidnut for pressing the latter longitudinally toward the threaded part ofthe body.

6. In an adjustable brakedevenconnection, an adjusting-screw, a headhavmg a threaded portion engaged by said screw, a nut disposed upon saidscrew, means for preventing relative rotationof said nut and the head, aspring engaging said nut and pressing the same longitudinally of thescrew, and an abutment held in fixed longitudinal relation to the headand engaging said spring to hold the same against the nut. I

7. In a slack-adjuster for brakes, a brakelever-connection comprisingterminal heads connected with the brake-levers, and an adjusting rodconnecting said heads and rotatable relatively thereto, a portion ofsaid rod being threaded and engaging a threaded por tion of one head, aclutch-sleeve mounted rotatively upon said rod, means for maintaining auniform frictional engagement between said sleeve and the rod, means foractuating. the clutch-sleeve in directions alternating astne brakes arevapplied and released, and means for maintaining between said adjListing-rod and each of the heads a longitudinal pressure which isconstant in direction. l

8. In a slack-adjuster'for brakes, a brakelever -connection comprisingterminal heads pivotally connected with the brake-levers, andanadjusting-rod connecting said heads and rotatable relatively thereto,a portion of said rod being threaded and engaging a threaded portion ofone head, a clutch-sleeve mounted rotatively upon saidrod, means foractuating the clutch-sleeve in directions alternating as the brakes areapplied and released, means for maintaining. between said adjListing-rod and each of the heads a longitudinal pressurewhich isconstant in direction but-variable in amount according to thelongitudinal stresses between the brakelevers, andv means formaintaining a uniform clutch-friction between the clutch-sleeve andrelatively rotatable to vary the length of the connection, meansfrictionally connected with one of said members for rotating the same toelongate the connection when'the slack is excessive, and a detentcarried by one of: said threaded members and yioldingly "en gaged withthe other, the latter member hav ing a portion engageable with saiddetent to prevent extension of the connection beyond a predeterminedlimit. 10. In a slack-adjuster for brakes, an adj Listing-rod having athreaded portion, a tubular head inclosing the threaded portion of theadjusting-rod'to form a housing there for, said headbeing internallythreaded to engage the threaded portion of the rod, the head having alateral opening intersecting the threaded portion in which the rod isenafter the brake-shoes engage the gaged, a member movably disposed insaid lateral opening, the rod having an undercut recess in the sidethereof adapted to register with said lateral opening, and means foractuating said member to enter said recess as the latter comes intoregister therewith during rotation of the rod and to thereby preventfurther rotation of the rod.

11. In a slack-adjuster for brakes, a brakelever connection having aforked head straddling the brake-lever, an adjusting-rod rotativelyconnected with said head, a fulcrumpin extending transversely throughthe forked head and brake-lever to pivotally connect the same, andcheek-plates carried by the head and arranged to closely embrace thesides of the lever at a distance from said fulcrum-pin to limit movementof the head about the axis of the adjusting-rod when the fulcrum-pinbecomes worn and loose.

12. In a slack-adjuster for brakes, a brakelevcr-connection comprisingterminal heads pivotally connected with the brake-levers, and anintermediate rod connecting said heads, said rod having at one end ascrewthreaded connection with one of the heads and having at the otherend a shouldered reduced portion extending through the other head androtatable therein, and means main taining frictional connection betweensaid rod and said other head.

13. In a slack-adjuster for brakes, a brakelever-connection comprisingterminal heads pivotally connected with the brake-levers, and anintermediate rod connecting said heads, said rod having at one end ascrew threaded connection with one of said heads, the other of saidheads having tubular portion to receive said rod, said rod having ashouldered reduced portion extending through said other head androtatable therein, and means for maintaining frictional connectionbetween said rod and said other head.

14. In a slack-adjuster for brakes, a brakesaid rod, said rod having ashouldered reduced portion extending through said other head androtatable therein, and means for main taining a definite normal frictionbetween said rod and said other head.

15. In a slack-adjuster for brakes, a brakelever connection comprisingterminal heads pivotally connected with the brake-levers, and anintermediate rod connecting said heads, said rod having at one end ascrew threaded connection with one of said heads, the other of saidheads having a tubular por tion to receive said rod, said rod having ashouldered reduced portion extending through said other head androtatable there-- in, a nut threaded on the reduced portion of said rodand holding said rod and said other head against coming EL132L1'i,'LI1ClH1BHDS cooperating between said rod and said other head tomaintain friction between the same for the purposes described.

16. In aslack-adjuster for brakes, a brakelever-connection comprisingterminal heads pivotally connected with the brake-levers, and anintermediate rod connecting said heads, said rod having at one end ascrew threaded connection with one of said heads and having at the otherend a shouldered reduced portion extending through the other head androtatable therein, and means maintaining f iction'al connection betweensaid rod and one of said heads for the purposes described.

17. In a slack-adjuster for brakes, a brakelever-connection comprisingterminal heads pivotally connected with the brake-levers and anintermediate rod connecting said heads, said rod having at one end ascrew threaded connection with one of said heads and having at the otherend a swivel connection with the other head, a clutching meanscooperating with said rod and one of the brake-levers for automaticallyturning said rod for the purposes specified, and means maintainingfrictional connection between said rod and one of said heads for holding,said rod against turning backwards during the reverse movement of saidclutching means.

CHARLES O. ANDERSON.

